JPH11105155A - Method and apparatus for molding annular member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily mold a bead filler almost uniform in wall thickness in its peripheral direction and stable in shape. SOLUTION: The linear rubber element 34 ejected from an injection molding machine 30 is laminated on a molding disc 14 rotated around its axis while spirally bonded to the disc 14 so as to form a plurality of layers to mold a bead filler 35 and, therefore, a thickned bonded part is not present on the periphery of the bead filler 35 at any place and, even if there is a slight change in the thickness or the like of the linear rubber element 34, the change is dispersed in the peripheral direction of the bead filler to be averaged by winding the rubber element many times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a molding method and apparatus for molding an annular member such as a bead filler.

[0002]

2. Description of the Related Art Conventionally, an annular member made of unvulcanized rubber, for example, a bead filler used for manufacturing a pneumatic tire, is obtained by removing a band-shaped rubber which becomes thinner from a die of an extruder toward one side in a width direction. After being extruded, the belt-like rubber is once wound up into a roll, and then, while the belt-like rubber is being unwound from the roll, it is supplied to the outside in the radial direction of the bead core, and the other end in the width direction, which is the thick side, is in close contact with the outer peripheral surface of the bead core. At the same time, the belt-shaped rubber is cut into approximately one circumferential length of the bead core, and then the cut-out rubber piece is formed by butt-joining the start and end of the cut rubber piece.

[0003]

However, in such a conventional method and apparatus for forming a ring-shaped member, the cut-out rubber piece is formed into a ring by butt-joining the start and end of the cut-out rubber piece. The thickness of the formed annular member (bead filler) is increased at one location on the circumference, that is, at the joining portion, and as a result, the thickness becomes uneven in the circumferential direction. Further, when the belt-like rubber is formed by extrusion as described above, the thickness of the belt-like rubber slightly changes depending on the position in the longitudinal direction, but such a change remains in the annular member (bead filler) as it is, and the thickness in the circumferential direction is reduced. There is also a problem of non-uniformity. When the bead filler whose thickness is uneven in the circumferential direction as described above is used for manufacturing a pneumatic tire, the uniformity of the pneumatic tire is reduced. Further, when the annular member (bead filler) is deformed from a substantially cylindrical shape to a substantially truncated conical final shape, the radially outer portion (one side in the width direction of the rubber piece) of the annular member (bead filler) becomes large. Because of the stretching, there is also a problem that the shape becomes unstable in an attempt to return to the initial substantially cylindrical shape.

According to the invention, the thickness is substantially uniform in the circumferential direction,
Moreover, it is an object of the present invention to provide a molding method and an apparatus capable of easily molding an annular member having a stable shape.

[0005]

SUMMARY OF THE INVENTION The purpose of the invention is as follows.
By feeding and attaching a linear rubber body composed of unvulcanized rubber to the attachment surface while moving in a radial direction when a molding disk having an attachment surface on an end surface is rotating around an axis. Secondly, the annular member is formed by laminating a plurality of spiral-shaped linear rubber bodies on the attachment surface to form an annular member, and secondly, the end surface has an attachment surface and rotates around an axis. And a supply means for supplying the linear rubber body to the attachment surface of the molding disk while moving in a radial direction, and supplying the linear rubber body to the attachment surface of the rotating molding disk by the supply means. This can be achieved by an annular member forming apparatus in which a plurality of spiral linear rubber bodies are stacked on the attachment surface to form an annular member by supplying and attaching while moving in the radial direction. it can.

A linear rubber body is supplied to the molding disk by a supply means while rotating the molding disk about an axis, and the linear rubber body is adhered to the attachment surface. At this time,
The linear rubber body is moved in the radial direction by the supply means, and the linear rubber body attached to the attachment surface is formed into a spiral shape, and a plurality of such spiral linear rubber bodies are laminated on the attachment surface. To form an annular member. Here, in the annular member formed in this way, the thickened joint does not exist anywhere on the circumference, and moreover, the beginning of the linear rubber body,
The break in the member that occurs at the end is because the linear rubber body is thin,
The thickness of the annular member is hardly affected, whereby the thickness of the annular member can be made substantially uniform in the circumferential direction. In addition, even if the thickness, thickness, etc. of the linear rubber body supplied to the molding disc slightly change depending on the position in the longitudinal direction, such a change occurs because the linear rubber body is wound many times on the molding disc. It is distributed and averaged in the circumferential direction,
As a result, the thickness of the formed annular member becomes substantially uniform in the circumferential direction. For this reason, when this annular member (bead filler) is used for manufacturing a pneumatic tire, the uniformity of the pneumatic tire can be improved. Further, a linear rubber body is spirally adhered to the end surface (adhering surface) of the molded disk to form an annular member (bead filler).
, The annular member (bead filler) has a flange shape similar to the final shape, and as a result,
It is stable in shape and easy to handle.

According to the third aspect of the present invention, it is possible to reduce the change in the weight (thickness, thickness, etc.) of the linear rubber body in the longitudinal direction, and the rubber injected in one shot. The amount can be made uniform, whereby the thickness of the annular member can be made uniform. In addition, since the linear rubber body having a high temperature immediately after injection molding is supplied to the adhesion surface, the adhesion is strong and the adhesion is ensured. Furthermore, according to the structure described in claim 4, since the annular member at the end of molding has a substantially final shape, the amount of deformation when deformed to the final shape is small, and as a result, the shape is stable. I do.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, reference numeral 11 denotes a supporting case, and a rotating shaft 12 extending vertically is rotatably supported by the supporting case 11, and a horizontal disk-shaped supporting plate 13 is provided on an upper end of the rotating shaft 12. Has been fixed. A substantially ring-shaped forming disk 14 coaxial with the rotating shaft 12 is fixed to the support plate 13, and the forming disk 14 has an attachment surface 15 on an upper end surface. The adhering surface 15 has a shape similar to one surface of a bead filler (annular member) having a final shape, which will be described later, and here has a shape slightly inclined downward toward the outside in the radial direction, that is, a conical surface.
As a result, the shape of the bead filler at the end of molding is almost the same as the final shape, and as a result, the deformation amount when the bead filler is deformed to the final shape is reduced, and the shape is stabilized. Reference numeral 16 denotes a bead chuck supported at a radially inner end of the forming disk 14, and the bead chuck 16 includes a plurality of arcuate chuck segments 17 movable in the radial direction, and has a cylindrical shape as a whole. I have. The bead chuck 16 grips the bead core 18 placed on the radially inner end of the forming disk 14 from the radially inner side by centering the bead core 18 placed on the radially inner end of the forming disc 14 by the chuck segment 17 moving radially outward in synchronization. . Reference numeral 19 denotes a servomotor as a rotating means built in the support case 11, and an output shaft 20 of the servomotor 19.
Is transmitted to the rotating shaft 12 via a belt or the like (not shown), and the rotating shaft 12, the support plate 13, the forming disc 14,
The bead chuck 16 is integrally rotated around an axis (rotary shaft 12).

Reference numeral 25 denotes a flat base provided on the side of the support case 11, on which a pair of horizontal guide rails 26 extending in parallel to a plane including the axis of the forming disk 14 is laid. I have. Reference numeral 27 denotes a movable table installed directly above the base 25, and the movable table 27 is slidably supported by the base 25 via a plurality of slide bearings 28 attached to the lower surface and the guide rail 26. . As a result, the movable table 27 can move along the guide rail 26 by the operation of a servo motor (not shown). An elevating table 29 is supported on the movable table 27 so as to be able to move up and down,
The lift table 29 is moved up and down by the operation of a servo motor (not shown). The operation of the servo motor 19, the servo motor that drives the movable base 27, and the lift base 29 is controlled by control means (not shown).

An injection molding machine 30 as a supply means is mounted on the upper surface of the elevating table 29. The injection molding machine 30 extends in a direction orthogonal to the guide rail 26. Then, the injection molding machine 30 injects the unvulcanized rubber supplied to the heating cylinder 32 through the hopper 31 from the nozzle 33 with a plunger (not shown), and forms a continuous high-temperature linear rubber body 34. The linear rubber body 34 immediately after the injection is supplied to the attachment surface 15 of the molding disk 14 to be pressed and adhered. At this time, when the movable table 27 is moved along the guide rail 26 together with the elevating table 29 and the injection molding machine 30, the nozzle 33 moves in the radial direction just above the adhesion surface 15 along the normal line. surface
The linear rubber body 34 attached to 15 has a spiral shape. Further, as described above, the attachment surface 15 of the molding disk 14 is slightly inclined downward toward the outside in the radial direction, but when the linear rubber body 34 is attached to the attachment surface 15, 29. The injection molding machine 30 is moved up and down so that the linear rubber body 34 is always adhered to the attachment surface 15. In this embodiment, the cross section of the linear rubber body 34 is a square column, but may be a square plate, a polygonal column, or a column. If the linear rubber body 34 supplied to the molding disk 14 is molded by the injection molding machine 30 as described above, the weight (thickness, thickness, etc.) of the linear rubber body 34 in the longitudinal direction changes. Can be made smaller than when molded by an extruder, and the amount of rubber injected in one shot can be made uniform, so that the thickness of a bead filler described later can be made uniform in the circumferential direction. . Moreover, if the linear rubber body 34 having a high temperature immediately after being injected from the injection molding machine 30 is supplied to and adhered to the adhesion surface 15, the adhesion is strong and the adhesion is ensured.

Next, the operation of the first embodiment of the present invention will be described. First, after supplying the bead core 18 to the forming disk 14 and mounting it on the radially inner end thereof, the chuck segment 17 of the bead chuck 16 is synchronously moved outward in the radial direction, and the bead chuck 16
Hold 18 from the inside in the radial direction while centering.
Next, the movable table 27 and the elevating table 29 are moved by operating the servomotor, and the nozzle 33 is moved to the vicinity of the intersection between the outer peripheral surface of the bead core 18 and the attachment surface 15 of the forming disk 14. next,
The molding disc 14 is rotated around the axis by the servo motor 19, and the injection molding machine 30 is operated to inject the unvulcanized rubber continuously from the nozzle 33 in a linear manner, thereby forming a high temperature linear rubber body 34 immediately after the injection. It is supplied to the adhesion surface 15 to be adhered (adhered). At this time, the movable table 27 is moved along the guide rail 26 by the servo motor, so that the nozzle 33 and the linear rubber body 34 are radially moved by the same distance as the width of the linear rubber body 34 per rotation of the forming disk 14. The linear rubber body 34 attached to the attachment surface 15 is moved outward to form a spiral shape. At this time,
Since the attachment surface 15 of the molding disk 14 is slightly inclined downward toward the outside in the radial direction, the elevator table 29 and the injection molding machine 30 are lowered by the servomotor, and the linear rubber body 34 is
Is always adhered to the attachment surface 15. Here, as the attachment position of the linear rubber body 34 to the attachment surface 15 is displaced radially outward, one circumference of the linear rubber body 34 becomes longer,
Correspondingly, the rotation speed of the molding disc 14 is gradually decreased by the control means, or the molding speed of the linear rubber body 34 is gradually increased, so that the linear rubber body 34 having the same cross-sectional shape is always formed. 14 to be attached. When the spiral linear rubber body 34 of the first layer is attached to the molding disk 14 in this manner, the injection molding machine 30 is moved by the servo motor to move the nozzle 33 between the outer peripheral surface of the bead core 18 and the first surface. It is moved to the vicinity of the intersection with the linear rubber body 34 of the layer.
Thereafter, the linear rubber body 34 is injected from the nozzle 33 of the injection molding machine 30 while rotating the molding disk 14 in the same manner as described above, and the linear rubber body 34 of the second layer is formed on the linear rubber body 34 of the first layer. The rubber body 34 is laminated. When a plurality of linear rubber bodies 34 are laminated on the attachment surface 15 in this manner, as shown in FIG. An annular member having a thinner cross section and a predetermined shape, here a bead filler 35, is formed.

Here, in the bead filler 35 molded in this way, the thickened joint does not exist anywhere on the circumference, and at the beginning and end of the linear rubber body 34. Since the linear rubber body 34 is thin, the breakage of the generated member hardly affects the thickness of the bead filler 35, whereby the thickness of the bead filler 35 becomes substantially uniform in the circumferential direction. The linear rubber body supplied to the molding disc 14
Even if the thickness, thickness, etc. of 34 slightly changes depending on the position in the longitudinal direction, since the linear rubber body 34 is wound around the forming disk 14 many times, such changes in thickness, etc. are dispersed in the circumferential direction. Averaged, thereby forming the bead filler
The thickness of 35 is substantially uniform in the circumferential direction. For this reason, when the bead filler 35 is used for manufacturing a pneumatic tire, the uniformity of the pneumatic tire can be improved. Furthermore, since the linear rubber body 34 is spirally adhered to the end surface (adhering surface 15) of the molding disk 14 to form the bead filler 35, the bead filler 35 has a flange shape similar to the final shape. As a result, the shape is stable and the handling becomes easy.

FIG. 3 is a diagram showing a second embodiment of the present invention. In this embodiment, the linear rubber body 37 attached to the radially inner portion of the molding disk 14 is made of a kind (for example, high hardness) of unvulcanized rubber, while the linear rubber member 37 is attached to the radially outer portion. The linear rubber body 38 is made of different types of unvulcanized rubber (for example, having low hardness). As a result, the molded bead filler 39 is composed of two types of rubber with the boundary 40 at the center in the radial direction. And when molding such a bead filler 39,
In order to inject two types of linear rubber bodies 37 and 38, it is preferable to install another injection molding machine. When the bead filler is composed of three types of rubber, three injection molding machines may be provided.

In the above-described embodiment, the linear rubber body 34 is spirally attached radially outward on the molding disk 14, but in the present invention,
The adhesive may be applied while repeating inward in the radial direction or inward in the radial direction. In the above-described embodiment, the attachment surface 15 of the forming disk 14 is slightly inclined downward toward the outside in the radial direction, but in the present invention, the shape is slightly inclined upward toward the outside in the radial direction. And may be flat. Further, in the above-described embodiment, the linear rubber body 34 immediately after being injected from the injection molding machine 30 is supplied to and adhered to the molding disk 14, but in the present invention, the injection molding machine, the extruder The linear rubber body formed by such as is wound up once on a roll,
If necessary, the roll may be unwound from the roll and adhere to the forming disc.

[0015]

As described above, according to the present invention, an annular member whose thickness is substantially uniform in the circumferential direction and whose shape is stable can be easily formed.

[Brief description of the drawings]

FIG. 1 is a partially broken whole perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II of FIG.

FIG. 3 is a sectional view similar to FIG. 2, showing a second embodiment of the present invention;

[Explanation of symbols]

 14 molding disk 15 attachment surface 30 supply means 34 linear rubber body 35 annular member

Claims (4)

[Claims] 1. A linear rubber body made of unvulcanized rubber is supplied while being moved in the radial direction to the adhering surface when a molding disk having an adhering surface on an end face is rotating around an axis. A method for forming an annular member, wherein a plurality of spiral linear rubber bodies are laminated on the attachment surface to form an annular member. 2. A molding disk having an attachment surface on an end surface and rotatable around an axis, and a supply means for supplying a linear rubber body to the attachment surface of the molding disk while moving the linear rubber body in a radial direction, By supplying the linear rubber body to the attachment surface of the rotating forming disc while moving it in the radial direction by the supply means and attaching it, a plurality of spiral linear rubber bodies are laminated on the attachment surface to form an annular shape. An apparatus for forming an annular member, wherein the member is formed. 3. The supply means is an injection molding machine for injecting unvulcanized rubber in a continuous linear form, and the linear rubber body immediately after being injected from the injection molding machine is supplied to an adhesion surface. An apparatus for forming an annular member according to claim 2. 4. An apparatus for forming an annular member according to claim 2, wherein the adhered surface of said forming disk is formed into a shape approximating one surface of an annular member having a final shape, and the formed annular member has a substantially final shape.